As we observe Martin Luther King Jr. Day, that’s sobering to consider.

“We haven’t achieved anything like the racially just and equal society that MLK envisioned,” says Ralph Richard Banks, a professor at Stanford Law School who specializes in African American issues. But that increase might also be due to more willingness to report incidents, as opposed to shrugging off bigotry, as well more awareness of what amounts to discrimination.

“But at a minimum,” says Derek Avery, a leading scholar in workplace discrimination at the Fox School of Business at Temple University, “those numbers suggest that we’re not heading in the direction that one would anticipate, as we approach 50 years after the passage of the Civil Rights Act of 1964.”

On the bright side, “racism in American society is less virulent and widespread now than its ever been in our history,” says Banks. On the downside, our discrimination laws were designed to catch precisely the kind of discrimination that’s much less obvious than it was decades ago.

“The law is good at punishing the overtly racist employer or the serial groper. But for other types of discrimination, the law remains a disorderly jumble,” says Keith Cunningham-Parmeter, an associate professor at Willamette University, whose research focuses on employment discrimination. Today’s workers, he says, “must deal with a legal regime that was designed around their grandparents’ workplaces.”

It’s a jumble because workplace discrimination law is in many ways anathema to one of the founding principles of American business: at-will employment. The vast majority of Americans are employed at-will, which means their supervisors can fire them whenever and for whatever reason they want.

Whatever reason they want, except that is for the ones that Congress declares illegal, like race, color, religion, sex and national origin. Barring the requirements of some state and local laws, everything else is fair game, like your sexual orientation, weight, appearance, clothes, hair style or predilection for yogurt at 11 a.m. Unions are pretty good at ensuring that workers are only fired for a “just cause,” but only a sliver of the American workforce today is unionized.

“Employers want to retain the right to be irrational,” says Cunningham-Parmeter, and so there is a lot of resistance to any expansion of discrimination law. But lawyers can be a creative bunch, and new kinds of discrimination claims are finding some success.

Claims of “family responsibility discrimination” have almost quadrupled over the past decade, according to The Center for WorkLife Law, and plaintiffs are winning more of these than any other type of employment case. Family responsibility discrimination is when an employer penalizes an employee for taking care of children, sick partners or older parents, even though the employee’s work is up to scratch.

These claims are usually filed under sex discrimination. Denying a man a promotion for taking more time with his family, for example, could be seen as punishing him for violating a gender stereotype. When a working mother isn’t given a business trip because she’s a mother, your punishing her for supposedly fulfilling one.

Weight, grooming and appearance discrimination claims are also usually filed under sex discrimination, since weight, grooming and appearance standards often fall disproportionately on womankind. But if you do it gender neutrally, discriminating against someone on the basis of their looks or waistline is totally legal, unless your looks or waistline qualify as a disability.

Even what might seem like outright discrimination may require some legal wrangling, since it can be so much more subtle these days. For example, there’s what Avery calls “well-intentioned” discrimination. An employer may not hire or promote a black person to a job in a more racist region of the U.S., “for their own good.” Or a supervisor may send a man, as opposed to a woman, on a business trip to a part of the world that is “not receptive to embracing the idea of female leadership,” in Avery’s careful phrasing.

People also tend to mentor people who remind them of themselves at that age. “‘I’m going to promote the guy who’s a member of my country club,’” is the attitude, says Avery, while these employers “ignore the fact that the members of your club look like you.”

And then there are the immeasurable prejudices, the kind that lurk quietly in our minds, shading our relationships and decisions. “Everyone carries around images in their head of who’s a good worker and who’s not,” says Banks, “who’s smart and who’s not.”

So even as discrimination becomes more difficult to prosecute, more forms of discrimination are getting prosecuted. In the landmark 2009 case of Ricci v. DeStefano, the Supreme Court ruled that, yes, white firefighters could sue for “reverse” discrimination. That’s “a large leap from Title VII’s origins,” says Cunningham-Parmeter. We’ve come so far that employment discrimination law has turned back on itself.

Perhaps it’s because the number of workplace discrimination claims continues to increase that people systematically underestimate the number of protections they really have. Not only are people’s rights to free speech and privacy sharply curbed at work, but employers can usually fire you, or deny you a promotion, just because they don’t like your face.

In some ways, tackling discrimination was much easier 50 years ago. “In retrospect, at least, it seems that the challenges that they confronted, while monumental, were fairly straightforward,” says Banks. “Now people of goodwill really can differ over what to do.”